In several industrial and commercial applications, the purchase and sale of fluid products typically occurs as a bulk transfer. Where relatively high volumes are involved, it is obviously impractical to package the fluid in containers and transfer it on that basis. Because of the impracticality of containerization, purchasers and sellers of fluids on such basis have determined that it is in their economic best interests to transfer such fluids in bulk and somehow effect a measurement of flow to determine the volume transferred and periodically sample the fluid for consistency and quality as the basis for the purchase and sale. As a consequence, a science has evolved about such commercial transactions which has as its root premise, the need to be able to accurately measure fluid volumes as the fluid continuously flows past a measuring point, and to obtain samples from which the makeup and quality of the fluid being transferred can be ascertained.
Examples of such transactions include volume users of combustible fuels such as commercial airports and military installations. In such instances, it is not uncommon for fuels to be piped into an installation directly from a refinery rather than to truck it in with tankers. Likewise, it has been a common practice for many years to buy and sell crude oil from a producing well by measuring the quantity of oil from the well as it flows through a pipeline, and at the same time, evaluating the quality of the crude to determine the price due the seller from the buyer at any particular point in time.
In the latter example, the quality of the crude is exceedingly important both to the buyer and the seller and the price to be paid is heavily dependent upon that quality. Crude pumped from a well will have a measurable specific gravity, and may often be polluted with certain emissible fluids such as water and undesirable salts. In order to ascertain the quality of bulk fluids flowing through a pipeline, the task facing the buyer is to extract periodic, essentially homogeneous, samples of the crude without interrupting flow and under such conditions as to reasonably assure the buyer that the sample extracted is representative. The seller, of course, has an equal interest in being assured that the sample extracted accurately reflects the gravity of the crude, which plays a major role in the price which he is to receive.
As will be described hereinafter the present invention addresses the problem of extracting accurate samples of a kinetic fluid flowing under significant pressures, and is uniquely capable of serving this vital interest in a very simple and inexpensive manner. More specifically, the present invention automatically collects and stores periodic samples of fluid under pressure in such a manner as to preserve the character and integrity of such samples for later testing.
Thus it is a primary objective of the present invention to periodically receive, segregate and store samples of fluid, such as crude oil, flowing under pressure in a pipeline, maintaining the fluid samples under pressure at all times until such time as the collected samples can be analyzed for whatever commercial purpose the buyer and/or seller deem appropriate.
Since many of the fluids sampled by the apparatus of the present invention are both volatile and flammable, it is a further objective to isolate and segregate fluid samples so as to avoid contact with oxygen and a potential source of ignition.